CN1202786C - Absorbent article - Google Patents

Abstract

An absorbent article comprising a liquid-permeable surface in contact with the skin, a liquid-impermeable surface not in contact with the skin, and a liquid-storage absorbent member interposed between the liquid-permeable surface and the liquid-impermeable surface , the absorbent member includes at least one absorbent body and an elastic body, the absorbent body includes at least one fiber aggregate and a superabsorbent polymer, the fiber aggregate includes the same or different fibers, and the elastic body satisfies the following conditions ( 1) and (2), and including heat-fusible fibers as a main component: (1) the fiber orientation ratio of the elastomer is lower than 5.0, and (2) the flexural hardness of the elastomer is 0.05-2.0 gf.cm.

Description

absorbent article

technical field

The present invention relates to absorbent articles such as sanitary napkins and disposable diapers. More specifically, the present invention relates to an absorbent article that prevents shape loss when worn, fits well to the wearer's body, and has high absorbency.

Background technique

Conventional techniques related to absorbent articles having elastic bodies include Japanese Patent Application Laid-Open Nos. 59-225058, 6-237956, 6-54879, 2-11138 and 6-319769.

However, these conventional techniques have disadvantages as follows.

In the sanitary napkin disclosed in Japanese Patent Application Laid-Open No. 59-225058, when the amount of released body fluid is large, leakage of the body fluid occurs because the absorbency of the absorbent body is insufficient. Because of insufficient bonding of the absorbent body and the leak-proof body (elastomer), the former may twist apart from the latter, resulting in reduced absorbency and liquid leakage.

In the sanitary napkin disclosed in Japanese Patent Application Laid-Open No. 6-237956, thermoplastic fibers are dispersed in the absorbent body, so that a continuous thermoplastic fiber layer throughout the absorbent body results in insufficient elasticity. The presence of dispersed thermoplastic fibers reduces the absorbency or capacity of the absorbent body. It is assumed that the thermoplastic fibers form a continuous layer. This continuous layer intercepts the layer of ground pulp contained in the absorbent body. Causes to hinder liquid penetration and diffusion in the absorbent body.

In the sanitary napkins disclosed in Japanese Patent Application Laid-Open Nos. 6-54879 and 2-11138.

The bonding between the absorbent body and the elastic layer or between the absorbent core and the deformable body of the sanitary napkin is insufficient, so that the elasticity of the elastic layer or the deformable body cannot be fully exerted.

Japanese Patent Application Laid-Open No. 6-319769 proposes an underwear liner, which has very poor absorbency because a septum made of foamed material lacks liquid absorbency. In addition, the bond between the septum and the absorbent body is not sufficient to make it sufficiently leak-proof.

Contents of the invention

It is an object of the present invention to provide an absorbent article that prevents deformation or twisting when worn, fits well to the wearer's body, and has high absorbency.

As a result of extensive studies, the present inventors found that the above object can be achieved by an absorbent article having an absorbent member including an absorbent body having a specific structure and an elastic body having specific physical properties.

They also found that the above object can be achieved by an absorbent article having an absorbent member which can be formed by joining an absorbent body and an elastic body in a specific joining manner to form an integral body.

The present invention has been accomplished based on the above findings. That is, the above objects are achieved by an absorbent article comprising a liquid-permeable surface in contact with the skin, a liquid-impermeable surface not in contact with the skin, and an embedded liquid-permeable A liquid-storage absorbent member between the surface and the liquid-impermeable surface, the absorbent member comprising at least one absorbent body and an elastomer. The absorbent body includes at least one fiber aggregate including the same or different fibers and a superabsorbent polymer. The elastic body satisfies the following conditions (1) and (2). It also includes heat-fusible fibers as a main component (hereinafter referred to as the absorbent article of the first invention).

(1) The fiber orientation ratio of the elastomer is less than 5.0, and

(2) The bending hardness of the elastic body is 0.05-2.0gf.cm.

The present invention also provides an absorbent comprising a liquid-permeable surface in contact with the skin, a liquid-impermeable surface not in contact with the skin, and a reservoir-absorbent member interposed between the liquid-permeable surface and the liquid-impermeable surface. Sexual articles, the absorbent member includes at least one absorbent body and an elastic body, the absorbent body includes at least one fiber aggregate and a superabsorbent polymer, the fiber aggregate includes the same or different fibers, and the absorbent member Formed by a first joining means of covering the elastic body with the absorbent body or covering the absorbent body with the elastic body, and a second joining means for joining the absorbent body and the elastic body together by adhesive or stamping to form grooves ( Hereinafter, it is referred to as the absorber of the second invention).

Absorbent article according to the invention. Since the deformation of the absorbent article is prevented and the fit to the wearer's body is improved, it can also give the wearer a comfortable feeling when worn for a long time. In addition, because the absorbent article of the present invention has no side leakage and is closely attached Adapts to the wearer's body to ensure high absorbency.

Description of drawings

Fig. 1 is a perspective view of a sanitary napkin as an embodiment of the absorbent article according to the first invention.

Fig. 2 is a cross section along line A-A of Fig. 1 .

Fig. 3 is a cross section of an absorbent member of a sanitary napkin as the first embodiment of the absorbent article according to the second invention.

Fig. 4 is a cross section of an absorbent member of a sanitary napkin as a second embodiment of the absorbent article according to the second invention (corresponding to Fig. 3 ).

Detailed ways

A preferred embodiment of the absorbent article according to the first invention will be described below by taking a sanitary napkin as an example with reference to FIG. 1 , which is a perspective view of a sanitary napkin as an embodiment of the absorbent article according to the first invention, and FIG. 2 It is a cross-section along line A-A in Fig. 1.

The sanitary napkin 1 shown in FIGS. 1 and 2 has an elongated shape, and includes a topsheet 2 as a liquid-permeable contact surface, a backsheet 3 as an impermeable non-contact surface, and an embedded topsheet 2. and the liquid storage absorbent member 4 between the backsheet 3.

The topsheet 2 and the backsheet 3 are about the same size and project outwardly from respective peripheries of the absorbent member 4, ie opposite lateral sides and longitudinally opposite sides of the absorbent member 4. The surface sheet 2 and the back sheet 3 are joined to each other by, for example, heat sealing at the protruding portion.

As shown in Figures 1 and 2, in the sanitary napkin 1, the topsheet 2, the backsheet 3 and the absorbent member 4 are partially heat-pressed together, thereby forming a pair of grooves 5 and 5' on the lateral side portions. . The grooves 5, 5' are curved in the longitudinal direction of the sanitary napkin 1 towards the centerline.

The surface layer material 2 is a liquid-permeable sheet with a touch similar to underwear, for example, it is made of polyethylene (PE) fibers, polypropylene (PP) fibers, polyethylene terephthalate (PET) fibers, PET fibers, etc. / Non-woven fabrics made of PP conjugate fibers, etc., and porous films, such as porous polyethylene films.

The backsheet 3 comprises a liquid-impermeable film sheet made of thermoplastic resin, or a liquid-impermeable but air-permeable film sheet obtained by stretching a thermoplastic resin sheet containing filler.

The above structure is the same as conventional sanitary napkins.

In the sanitary napkin according to this embodiment, the absorbent member 4 comprises at least one absorbent body 6 comprising at least one fiber aggregate comprising the same fibers or different fibers, the elastic body 7 satisfies the following conditions (1) and (2) and includes heat-melt fibers as a main component:

(1) The fiber orientation ratio of the elastomer is less than 5.0, and

(2) The bending hardness of the elastic body is 0.05-2.0gf.cm.

In the absorbent member 4, the absorbent body 6 and the elastic body 7 are preferably integrally connected by at least two of the following joining methods selected from the group consisting of coating adhesive, punching to form grooves, embossing and thermal bonding .

Specifically, the absorbent member 4 includes an integral body of an absorbent body 6 in the form of a sheet and an elastic body 7 in the form of a sheet, and the entirety is about the same size as the absorbent body 6 . The absorber 6 is provided on the topsheet 2 side, and the elastic body 7 is on the backsheet 3 side.

The width ratio of the elastic body 7 to the absorbent body 6 is preferably 50% or higher. The elastic body 7 may be placed on the central portion in the width direction of the absorbent body 6 or two sheets of the elastic body 7 may be placed on opposite lateral side portions. In order to prevent deformation, it is particularly preferred that the absorbent body 6 and the elastic body 7 are of the same width.

The length ratio of the elastic body 7 to the absorbent body 6 is preferably 50% or more. It is particularly preferred that the two parts are of the same length.

The adhesive is applied to almost the entire surfaces of the absorbent body 6 and the elastic body 7, thereby joining them together. The bonding method is the first connection method to connect these two parts into a whole.

Adhesives used include hot melt adhesives. The manner and amount of adhesive applied are selected so as to keep the absorbent body 6 and the elastic body 7 in one piece even when a large amount of liquid is absorbed or vigorous body movement occurs.

The coating method can be freely selected, as long as the absorbent body 6 and the elastic body 7 are substantially fixed together over the entire area. For example, slot spray coating, spiral spray coating, multi-row bead coating, spot coating, etc. may be used.

The application pattern of the adhesive is not limited as long as the absorbent body 6 and the elastic body 7 can be bonded into one body. Interrupted patterns such as rows of beads (lines), dots (spaced spots) and spaced spirals may alternatively be used, as long as these patterns are suitable for the purpose described above.

In order to obtain sufficient adhesive stress for joining the absorbent body 6 and the elastic body 7 as a whole, the coating amount of the adhesive should be 1 g/m ² or more.

As shown in Fig. 2, the grooves 5, 5' provided on the opposite lateral side portions of the sanitary napkin 1 are the second connecting means for connecting the absorbent body 6 and the elastic body 7 together by punching. The grooves 5, 5' are formed by hot stamping the absorber 6 and the elastic body 7 together with the topsheet 2 and the backsheet 3.

The absorbent body 6 and the elastic body 7 in the absorbent member 4 are connected as a whole through two connection methods, that is, the first method of using an adhesive and the second method of forming grooves by punching. Therefore, even when the wearer's body changes with movement while wearing the sanitary napkin, separation of the absorbent body 6 and the elastic body 7 caused by deformation or distortion can be prevented, and thus the elasticity of the elastic body 7 can be fully exhibited. As a result, the sanitary napkin conforms well to the wearer's body while maintaining high absorbency.

The absorbent body 6 constituting the absorbent member 4 is an absorbent sheet comprising at least one fiber aggregate comprising the same fibers or different fibers and superabsorbent polymer particles. The superabsorbent polymer particles are dispersed in a single fiber aggregate or are sandwiched between two fiber aggregates in layers or in spots (spaced). The term "fibrous aggregate" as used herein refers to a sheet-like fibrous aggregate mainly composed of fibers, and includes ordinary paper, nonwoven fabrics and woven fabrics.

The fibers that make up the fiber aggregates include natural cellulose fibers such as wood pulp, cotton pulp, and straw pulp; regenerated cellulose fibers such as rayon and cuprammonium rayon; synthetic hydrophilic fibers such as polyvinyl alcohol fibers and polyacrylonitrile fibers; and synthetic fibers rendered hydrophilic, such as polyethylene fibers, polypropylene fibers, and polyester fibers rendered hydrophilic by treatment with surfactants.

Preferably, the superabsorbent polymer particles absorb and retain 20 or more times their own weight in liquid, and are capable of gelling upon absorption. Suitable superabsorbent polymers include starch, crosslinked carboxymethylcellulose, polyacrylic acid and its salts, and polyacrylate grafted polymers. Specifically, superabsorbent polymers include water-insoluble and hydrophilic cross-linked polymer particles that can absorb large volumes of fluid through ionic osmotic pressure and retain the absorbed fluid even under pressure. No leaks will occur. Such superabsorbent polymers are obtained by polymerizing acrylic acid, alkali metal acrylic acid salts (such as sodium or potassium salts) and the like, followed by crosslinking to form water-insoluble polymers.

In order to prevent deformation and improve absorbency, it is preferable that the absorbent body 6 has a thickness of 0.3-5 mm. The amount of the superabsorbent polymer dispersed in the absorbent body 6 is preferably 5 to 300 g/m ² from the viewpoint of improving absorbency. The basis weight of the absorbent body is preferably 21-500 g/m ² , still preferably 30-300 g/m ² , particularly preferably 50-200 g/m ² .

A preferred absorbent body is an absorbent sheet having a fibrous structure comprising an integral body of two fibrous aggregates, and further comprising a superabsorbent polymer in the structure. More specifically, the absorbent sheet is made of hydrophilic fibers, heat-fusible fibers or paper reinforcement, and superabsorbent polymers, and said superabsorbent polymers are not present in the absorption of absorbent liquids Instead of being on the surface of the absorbent sheet, they are dispersed inside the absorbent sheet and adhesively fixed to the hydrophilic fibers constituting the absorbent sheet. The unit weight of the dispersed superabsorbent polymer is 5-300 g/m ² , and the thickness of the absorbent sheet is 0.3-1.5 mm.

Particularly preferred absorbent bodies are made of hydrophilic fibers, heat-melt fibers or paper reinforcement, and superabsorbent polymer particles, and said superabsorbent polymer particles are not present in the absorbent sheet. on the surface, but dispersedly fixed in the fibrous structure. The unit weight of the dispersed superabsorbent polymer particles is 20-70 g/m ² , and the thickness of the absorbent sheet is 0.3-1.5 mm.

Still preferably, the above-mentioned absorbent sheet contains 3 to 30% by weight of heat-fusible fibers in its fibrous structure. In this absorbent sheet, the heat-fusible fibers are thermally fused with each other so that the structure of the sheet is maintained even when the sheet absorbs liquid. When the hot-melt fiber and the elastomer are thermally bonded together, a stronger cohesive force can be produced to connect them into a whole.

As the heat-fusible fibers, fibers that melt when heated to bond to each other can be used. Examples of such hot-melt fibers include polyolefin fibers such as polyethylene (PE), polypropylene (PP) and polyvinyl alcohol (PVA), polyester (PEs) fibers, PE/PP conjugate fibers, PE/PEs conjugate fiber, low melting point PEs/PEs conjugate fiber, PVA/PP conjugate fiber with hydrophilic surface, and PVA/PEs conjugate fiber. Conjugate fibers can be core/sheath or side-by-side. These heat-fusible fibers may be used alone or in admixture of two or more. PVA fibers soluble in hot water and core/sheath type PEs fibers are preferred heat-fusible fibers for use in the present invention.

The elastic body 7 constituting the absorbent member 4 includes a material that is deformable (eg, bent or compressed) by an external force and returns to its original shape substantially when the external force is removed. The elastic body 7 should satisfy the aforementioned conditions (1) and (2), and be mainly composed of heat-fusible fibers.

The condition (1) is that the fibers in the limiting elastomer 7 should have an orientation ratio lower than 5.0. The lower the fiber orientation ratio, the less oriented the fibers are in one direction. The minimum fiber orientation ratio is 1.0, which means that individual fibers can be oriented in each direction. At a fiber orientation ratio of less than 5.0, the fibers in the elastic body 7 are oriented in any direction, exhibiting a small degree of orientation, so that the elastic body 7 can be deformed according to each wearing manner. As a result, a sanitary napkin that does not undergo deformation and thus has stable absorbency can be obtained. The fiber orientation ratio of the elastomer 7 is preferably 1.0-3.0, still preferably 1.0-2.0.

The fiber orientation ratio was calculated from the transmittance of electromagnetic waves emitted in the longitudinal and width directions of the flat sheet of the elastomer 7 . Details of the measurement method will be described in Examples given later.

The condition (2) is that the restricting elastic body 7 should have a bending hardness of 0.05-2.0 gf.cm. If the bending hardness is lower than 0.05 gf.cm, the deformation preventing effect of the elastic body 7 is insufficient. If it exceeds 2.0gf.cm, the restoring force is too strong, giving the wearer an uncomfortable feeling. The bending hardness is preferably 0.10-1.0 gf.cm. Details of the method of measuring the bending hardness will be described in Examples given later.

The type of the elastic body 7 is not limited as long as it can meet the above requirements. It is particularly preferable that the elastic body 7 is formed of a nonwoven fabric mainly composed of the above-mentioned heat-melt fibers.

The heat-fusible fibers used in the elastomer 7 include various thermoplastic fibers. Examples of suitable heat-melt fibers include polyolefin fibers such as polyethylene (PE) and polypropylene (PP), polyester (PEs) fibers such as polyethylene terephthalate (PET), PE/PP conjugates fibers, PE/PEs conjugate fibers, PP/PEs conjugate fibers, low melting point PEs/PEs conjugate fibers, and low melting point PP/PP conjugate fibers (especially core/sheath type conjugate fibers). Conjugate fibers can be core/sheath or side-by-side. These heat-fusible fibers may be used alone or in admixture of two or more.

Although the hot-melt fibers may be in the form of short fibers or long filaments, it is preferable to use the form of short fibers so that the fibers can be randomly oriented in all directions to enhance the deformation rate and recovery of the elastic body 7 . It is still preferred that the fiber length of the short fibers is not more than 30mm, especially 2-10mm, in order to enhance deformability and elasticity.

For the above purpose, it is preferred that the individual heat-fusible fibers have at least one shape crimp, that is to say at least two shape crimps, in their longitudinal direction. It is particularly preferred that the fibers have at least one shape bend in their longitudinal direction to produce a three-dimensional shape, ie crimps in three-dimensional form.

The preferred fineness of the heat-fusible fibers is not more than 15 deniers, especially 1-10 deniers, because too thick fibers are too hard and tend to make the resulting elastomer stiff and prone to longitudinal bending.

As mentioned above, the elastic body 7 is mainly made of heat-fusible fibers. The expression "mainly made of heat-fusible fibers" used here means that the elastic body 7 contains enough heat-fusible fibers to express its elasticity. Therefore, the elastic body 7 may only consist of heat-fusible fibers, or may contain other materials than heat-fusible fibers, as long as the above conditions are satisfied. Other materials that may be used include natural cellulose fibers, regenerated cellulose fibers, and hydrophilic synthetic fibers. These materials are preferably incorporated in proportions of 5-60% by weight, based on the weight of the elastomer 7 .

It is preferable that the hot-melt fiber used in the elastomer 7 is treated with a surfactant to make it hydrophilic before or after being formed into the elastomer. In this case, the elastic body 7 can function as a part of the absorber, resulting in further improved absorbency.

There is no particular limitation on the method of producing a nonwoven fabric including heat-fusible fibers, and any conventional method may be used. When the hot-melt fibers are short fibers, the carded airflow method or suction thermal bonding method is suitable for producing bulky non-woven fabrics with a three-dimensional network structure.

The thickness of the elastic body 7 is preferably 0.1-7.0 mm, particularly preferably 0.5-5 mm. If the thickness is less than 0.1 mm, the elastic body may not have sufficient restoring force. If the thickness exceeds 7 mm, the resulting absorbent article is too thick to be used as a sanitary napkin, giving discomfort to the wearer when worn. Therefore, the above-mentioned range is preferable. When a nonwoven fabric is used as the elastic body 7, the term "thickness" used above refers to the thickness at a load of 0.5 g/cm ² .

The basis weight of the elastomer 7 is preferably 5-100 g/m ² , particularly preferably 15-80 g/m ² . If it is less than 5 g/m ² , the elastic body 7 does not have sufficient restoring force. If it exceeds 100g/m ² , a considerable external force is required to deform it, and the wearer feels uncomfortable when wearing it. Therefore, the above-mentioned range is preferable.

Preferably, the elastic body 7 has a volume recovery force (resilience force at 25% deformation after 75% compression) of 2-100 g, especially 10-50 g, when wet. If the volume restoring force is lower than 2 g when wet, the sanitary napkin does not have sufficient deformation preventing properties. If it exceeds 100 g, the wearer's feeling when wearing the sanitary napkin is uncomfortable because the restoring force is too large.

Volume restoring force was determined as follows.

A sample having a width of 40.0 mm and a length of 170 mm was cut from the elastomer. Spray 10 g of water over the entire sample. The opposite ends of the sample in the longitudinal direction are connected to form an overlap of 2 mm, and are pinned at two points to form a cylindrical sample with a height of 40.0 mm. The sample was placed on the platform of Tensilon RTM-25 (manufactured by Toyo Baldwin K.K.) with the longer side of the sample at the bottom side. Compress the specimen by 75% at a rate of 10 mm/min in a compression test mode and then allow it to rebound. The force at recovery to 25% deformation is measured and taken as the volume recovery force when wet.

When manufacturing sanitary napkins as shown in Figures 1 and 2, the connection method for connecting the absorbent body 6 and the elastic body 7 is not limited to the above-mentioned combination of adhesive and stamping grooves for connection, and other connection methods can also be used The combination.

In other words, at least two bonding methods may be selected from coating adhesive, punching to form grooves, embossing, and thermal bonding. Specifically, a connection method selected from the group consisting of coating adhesive, embossing, and thermal bonding may be used in combination with a connection method in which grooves are formed by punching. More specifically, a combination of punching grooves and embossing (in this case, embossing is applied to a part or the entire surface of the absorbent body 6 and elastic body 7) and punching grooves and heat A combination of bonding (in this case thermal bonding is performed on a part or the entire surface of the absorbent body 6 and the elastic body 7).

A preferred embodiment according to the second invention will be described below by taking a sanitary napkin as an example with reference to the accompanying drawings.

Fig. 3 is a cross section of an absorbent member of a sanitary napkin as the first embodiment of the absorbent article according to the second invention. Fig. 4 is a cross section of an absorbent member of a sanitary napkin as a second embodiment of the absorbent article according to the second invention (corresponding to Fig. 3 ).

Only the difference between the absorbent article of the second invention and the absorbent article of the first invention will be described. Although the same parts as the first invention are not described, corresponding explanations for the first invention also apply here. Components in FIGS. 3 and 4 are denoted by the same reference numerals as in FIGS. 1 and 2 .

Similar to the sanitary napkin shown in Figs. 1 and 2, the absorbent member 4 of the sanitary napkin shown in Fig. 3 includes a sheet-like absorbent body 6 and a sheet-like elastic body 7, but the sizes of these two parts are different. The absorbent body 6 and the elastic body 7 are connected as a whole by using at least two joining methods. The first joining method includes covering all upper and lower surfaces and opposite sides of the elastic body 7 with the absorbent body 6 . The second way of joining is to join the absorbent body 6 and the elastic body 7 together by applying an adhesive or punching and forming grooves on almost the entire surface of the two parts to be joined. In the embodiment shown in Figure 3, an adhesive is used as the second joining means to join the two parts together.

In this way, the absorber 6 and the elastic body 7 are connected as a whole through at least two joints. Therefore, similar to the sanitary napkins shown in FIGS. 1 and 2, even if the wearer's body shape changes with body movements when wearing the sanitary napkin, separation of the absorbent body 6 and the elastic body 7 due to deformation can be prevented, thereby Give full play to the elasticity of the elastic body 7 . As a result, the sanitary napkin can fit well to the wearer's body and ensure high absorbency.

Although the absorbent body 6 covers the entire periphery of the elastic body 7 in FIG. 3 , it is not necessary that the entire periphery of the elastic body 7 is completely covered by the absorbent body 6 .

The amount of adhesive used in the absorbent member 4 of Figure 3 is the same or lower than that used in the absorbent member of the sanitary napkin shown in Figures 1 and 2 for the following reasons. Assuming that the absorbent member 4 shown in FIG. 3 has the same size as the absorbent member 4 shown in FIGS. 1 and 2, the connecting surface area between the absorbent body 6 and the elastic body 7 of the former is about twice that of the latter. Therefore, the decrease in adhesion caused by the reduction in the amount of adhesive used can be compensated by the increase in the surface area of the joint.

In the absorbent member 4 of Fig. 3, it is preferable that the elastic body 7 covered by the absorbent body 6 is made of a hydrophilic material or made hydrophilic by appropriate treatment for the following reasons. When the liquid passes through the absorbent body 6 covering the upper surface of the elastic body 7 and reaches the elastic body 7 , if the elastic body 7 is hydrophilic, the liquid can pass through and reach the absorbent body covering the lower surface of the elastic body 7 . This makes liquid also absorbable in the bottom part of the absorbent body 6 below the elastic body 7, that is to say increases the absorbency. The material of the elastic body 7 preferably includes those used in the first invention. It is particularly preferable that the elastic body 7 satisfies the above-mentioned conditions (1) and (2) regarding the fiber orientation ratio and bending stiffness.

The absorbent part 4 of the sanitary napkin shown in Figure 4 includes an absorbent body 6 and an elastic body 7, which are connected as a whole by an adhesive, wherein the adhesive is used as a second joining method, and is applied on the opposite parts of the two parts. on the surface. Its structure is the same as the embodiment shown in FIG. 3 . The difference between the absorbent member 4 shown in FIG. 4 and the absorbent member 4 shown in FIG. 3 is that the relationship between the covering body and the covered body is reversed, which is the first connection mode.

That is, in the absorbent member 4 of FIG. 4 , all the upper and lower surfaces and the opposite sides of the absorbent body 6 are covered by the elastic body 7 , thereby forming the first joining mode.

The absorbent part 4 shown in Figure 4 is similar, the absorbent body 6 and the elastic body 7 are connected together by at least two kinds of joining methods, like this, can achieve the same absorbent part as the sanitary napkin shown in Figures 1 and 2 and Figure 3 beneficial effect.

Although the elastic body 7 covers the entire surface of the absorbent body 6 in FIG.

In the absorbent member 4 shown in FIG. 4, it is preferable that the elastic body 7 covering the absorbent body 6 is made of a hydrophilic material, or becomes hydrophilic by appropriate treatment, so that the liquid can be smoothly absorbed. It passes through the elastic body 7 and reaches the absorbent body 6 . In this case, a part of the elastic body 7 covering the absorbent body 6 or the whole of the elastic body 7 is formed of a hydrophilic material or made hydrophilic. The material of the elastic body 7 preferably includes those used in the first invention. It is particularly preferable that the elastic body 7 satisfies the above-mentioned conditions (1) and (2) regarding the fiber orientation ratio and bending stiffness.

Although the absorbent article according to the present invention (the first and second inventions) has been described according to the preferred embodiments, the absorbent article of the present invention is not limited thereto, and can be used without departing from the spirit and scope of the present invention. Various changes and improvements can be made therein.

For example, explanations about the absorbent articles of the first invention and the second invention are applicable to each other.

The absorbent article of the present invention is applicable not only to the sanitary napkins as described above, but also to nursing pads, underwear liners, disposable diapers, incontinence pads, and the like.

The effect of the present invention will be illustrated according to the examples below, but it should be understood that the explanation of the present invention is not limited thereto.

Example 1

An absorbent sheet having a total basis weight of 110 g/m ² and a thickness of 1 mm was used as the absorbent body. The absorbent sheet comprises a fiber aggregate having a basis weight of 80 g/m ² , the fiber aggregate being 97% by weight of cross-linked pulp (trade name "HBA", manufactured by Weyerhauser Paper Co., Ltd.) and 3 % by weight of polyvinyl alcohol binder fiber (trade name "Fibribond", manufactured by Sansho KK), the cross-linked pulp is obtained by treating wood pulp with a cross-linking agent, in the fiber aggregate 30 g/ ^m2 of superabsorbent polymer particles were also incorporated.

The three-dimensionally crimped PET/PE core/sheath conjugate fiber is formed into a net by the airflow method, the fineness of the conjugate fiber is 3 denier, and the length is 5mm, and then thermally bonded to obtain a non-woven fabric, and its unit weight is 30g /m ² , the thickness is 1mm. The resulting nonwoven fabric was used as an elastomer.

A hot-melt adhesive was spirally applied between the absorbent body and the elastic body with a basis weight of 10 g/m ² and a width of 40 mm, and then the absorbent body and the elastic body were bonded together to make an absorbent member.

The absorbent part is combined with the suction thermally bonded non-woven fabric as the contact surface and the breathable polyethylene sheet as the non-contact surface, and the above materials are connected into one by punching and forming grooves as shown in Figures 1 and 2. Overall, a sanitary napkin having the structure shown in Fig. 2 was obtained.

Example 2

An absorbent sheet having a total basis weight of 100 g/m ² and a thickness of 0.8 mm was produced as an absorbent body in the same manner as in Example 1 except that the amount of superabsorbent polymer particles incorporated was changed to 20 g/m ² .

The three-dimensionally crimped PET/PE core/sheath conjugate fiber is formed into a net by the airflow method, the fineness of the conjugate fiber is 4 denier, and the length is 5mm, and then thermally bonded to obtain a non-woven fabric, and its unit weight is 40g /m ² , the thickness is 1.2mm. The resulting nonwoven fabric was used as an elastomer.

A sanitary napkin having the structure shown in Fig. 2 was produced in the same manner as in Example 1, except that the above-mentioned absorbent body and elastic body were used.

Example 3

The three-dimensionally crimped PP/PE core/sheath conjugate fiber is formed into a net by the airflow method, the fineness of the conjugate fiber is 1.5 denier, the length is 7mm, and then thermally bonded to obtain a non-woven fabric, the unit weight of which is 30g /m ² , the thickness is 0.7mm. The resulting nonwoven fabric was used as an elastomer.

The absorbent body used in Example 2 was covered with the above-mentioned nonwoven fabric. The opposite surfaces of the two parts are bonded together by spirally applying a hot-melt adhesive with a unit weight of 10 g/m ² and a width of 40 mm to obtain an absorbent having the structure shown in Figure 4 part.

A sanitary napkin was produced in the same manner as in Example 1, except that the above-mentioned absorbent body and elastic body were used.

Comparative example 1

As the absorbent body, an absorbent sheet having a total basis weight of 110 g/m ² and a thickness of 1 mm is used, and the absorbent sheet includes fiber aggregates made of wood pulp with a basis weight of 80 g/m ² (trade name "NB -420", manufactured by Weyerhauser Paper Co., Ltd.), the fiber aggregate also contains 30 g/m ² of superabsorbent polymer particles.

The non-crimped PET/PE core/sheath type conjugate fiber is formed into a web by carding, the fineness of the conjugate fiber is 1.5 denier, and the length is 51 mm, and then thermally bonded to obtain a non-woven fabric, and its unit weight is 20 g /m ² , the thickness is 0.4mm. The resulting nonwoven fabric was used as an elastomer.

A sanitary napkin was produced in the same manner as in Example 1, except that the above-mentioned absorbent body and elastic body were used.

performance evaluation

The fiber orientation ratio and bending hardness of the nonwoven fabrics used as the elastomers in Examples and Comparative Examples were measured according to the following methods. The results obtained are shown in Table 1 together with the production method, basis weight and thickness of the nonwoven fabric under a load of 0.5 g/cm ² .

In order to evaluate the performance of the sanitary napkins obtained in Examples and Comparative Examples, the deformation rate was measured, and the deformability in actual use was evaluated as follows. The results obtained are also shown in Table 1.

1) Fiber orientation ratio

The measurement was performed with a molecular orientation analyzer "MOA-2001A" (trade name, manufactured by KS System K.K.).

2) Bending hardness

Cut the non-woven fabric into a sample with a length of 20 cm and a width of 10 cm. The bending moment of bending curvature was measured with "KES-FB2" (trade name, manufactured by Katotech, Inc.).

Fix the two longer sides of the sample on the chucks (the distance between the chucks is about 1 cm), and bend the sample to a curvature of 2.5 cm at a rate of curvature increase (deformation rate during bending) of 0.5 cm/sec ^{- 1} , and then return to a curvature of 1.5cm ^-1 . The bending moment was measured at this time, and it was taken as the bending hardness. When using specimens whose longer side is shorter than 20 cm, the measured bending stiffness shall be corrected to a length of 20 cm.

3) Deformation rate

8 g of defibrated horse blood was poured into the sanitary napkins obtained in Examples and Comparative Examples, and then applied to the exercise pattern of the female body. Carefully remove the napkin and measure its minimum width. The deformation rate was calculated from the measured width and the width before the test according to the following equation. The measurement was repeated 5 times to obtain the average value. As a criterion for evaluation, in this test, sanitary napkins that are hardly deformed in actual frequent use show a deformation rate of not more than 25%, while sanitary napkins that are often easily deformed show a deformation rate of 30% or more .

Deformation rate (%) = (the width of the sanitary napkin before the test - the width of the sanitary napkin after the test) / the width of the sanitary napkin before the test × 100 (%)

4) Evaluation in actual use (deformability)

35 female experts wore each sanitary napkin for 2 hours, and evaluated the feeling of deformation of the sanitary napkin during wearing by selecting the following 1-5 grades that they thought were most suitable for their feelings.

1--almost no deformation

2-- Difficult to deform

3 - hard to say

4--Easily deformed

5--Very easily deformed

Evaluation ratings were evaluated as a measure of deformability. The smaller the rating (closer to 1), the lower the deformability. The larger the rating (closer to 5), the higher the deformability.

Table 1 connection method elastomer Sanitary napkin performance fiber orientation ratio Bending hardness (gf.cm) Unit weight(g/m ² ) Thickness (mm) Fiber length (mm) Deformation rate (%) Evaluation in actual use (deformability) Example 1 Helical HM ^* Bonding + stamping to form grooves 1.1 0.5 30 1 5 15 1.4 Example 2 Helical HM bonding + stamping to form grooves 1.1 0.9 40 1.2 5 10 1.2 Example 3 Helical HM Bonding + Overlay 2.3 0.3 30 0.7 7 7 1.1 Comparative example 1 Helical HM bonding + stamping to form grooves 5.1 0.03 20 0.4 51 37 4.2

Note: "HM" stands for Hot Melt Adhesive

It can be clearly seen from Table 1 that compared with the comparative sanitary napkins, the sanitary napkins according to the embodiments of the present invention have a smaller deformation rate and are not easily deformed.

Claims (7)

1. An absorbent article comprising a liquid-permeable topsheet in contact with the skin, a liquid-impermeable backsheet not in contact with the skin, and Liquid-storage absorbent member between backsheets, the absorbent member comprising at least one absorbent body comprising at least one fiber aggregate and superabsorbent polymer, and an elastic body, the absorbent body having a thickness of 0.3-5 mm and a unit weight of 21-500g/m ² , the particles of the superabsorbent polymer are dispersed in a single fiber aggregate or sandwiched between two fiber aggregates in a layer or point form, the superabsorbent The unit weight of the polymer is 5-300 g/m ² , the fiber aggregate includes the same or different fibers, and the elastic body satisfies the following conditions (1)-(5) and includes heat-melt fiber as a main component , the absorbent body and the elastic body are connected as a whole by at least two connection methods selected from coating adhesive, stamping to form grooves, embossing and thermal bonding: (1) The fiber orientation ratio of the elastomer is 1.0-5.0, (2) The bending hardness of the elastic body is 0.05-2.0gf.cm, (3) The thickness of the elastic body is 0.1-7mm, (4) The unit weight of the elastomer is 5-100g/m ² , and (5) The wet volume recovery force of the elastomer is 2-100g. 2. The absorbent article according to claim 1, wherein said elastic body is formed of a non-woven fabric mainly composed of heat-fusible fibers. 3. The absorbent article according to claim 2, wherein said heat-fusible fibers forming said nonwoven fabric are short fibers having a length of 30 mm or less. 4. The absorbent article according to claim 2, wherein said heat-fusible fibers forming said nonwoven fabric alone have at least one bend in a longitudinal direction thereof. 5. The absorbent article according to claim 1, wherein the absorbent body contains 3-30% by weight of heat-fusible fibers. 6. The absorbent article according to claim 1, wherein said absorbent member is formed by a first joining method of covering the elastic body with the absorbent body or covering the absorbent body with the elastic body and for forming grooves by adhesive or punching to absorb It is formed by the second joining method that the body and the elastic body are connected together. 7. The absorbent article according to claim 6, wherein the absorbent member is formed by a first joining means of covering the entire surface of the elastic body with the absorbent body or covering the entire surface of the absorbent body with the elastic body.

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